Li-ion Battery System
The battery system is a key component of Koh Jik's micro-grid system. The battery pack used to provide the community with stored clean solar energy throughout the night. Now the batteries are degraded and the community is slowly losing access to this precious renewable energy storage. The battery storage now ends around 3 am which leaves the island in a complete "blackout" until the unsustainable diesel generator system is started around 5-6 am.
The Koh Jik ReCharge project aims to replace the existing lead-acid battery pack with new, state-of-the-art lithium-ion battery pack. This would be the first Li-ion powered micro-grid in Thailand!
Li-ion battery use has been surging mainly due to electric vehicles (EV) but their used is much broader. In a micro-grid application,
Li-ion batteries could significantly increase security of supply (through excellent storage) and drastically reduce green house gas emissions.
Current Battery System
Currently, a 240 kWh valve regulated lead-acid battery pack is operated in Koh Jik's micro-grid. The batteries were installed in early 2012 and are now reaching their end-of-life of about 5-7 years.
Li-on Battery System Upgrade
The global surge towards Li-ion battery storage can be explained by many factors.
One of the most attractive factors for a rural micro-grid such as Koh Jik is the lifetime of Li-ion batteries. Their lifetime can reach up to 1500-2000 cycles while Lead-Acid batteries can reach 500-1000 cycles. This lifetime difference is especially important to provide the community with clean energy storage for many years at an expected lower price per kWh storage. The Li-ion batteries being three times lighter than Lead-Acid and occupying a smaller space is also an important factor on a small community on a remote island when it comes to maintenance or replacement. This greater lifetime coupled with a charging battery efficiency of around 100% (compared to 85% in Lead-Acid) really make Li-ion the best candidate on the technical level.
The greater environmental friendliness of Li-ion batteries is also a determining factor to adopt them in a project such as ReCharge for their smaller carbon footprint and easier end-of-life disposal/recycling. They are safer to operate and overall a much cleaner technology.
Li-ion batteries now have a proven track record and despite the higher upfront cost incurred, the real cost of ownership is less than Lead-Acid due to enhanced lifetime and performance.